Pumping plant for high-pressure steam generators



' Dec. 6, 1927.

- 1,652,026 s. LOFFLER PUMPING PLAN! FOR HIGH PRESSURE STEM! GENERATORSFiled lay 11. 1926 3 Shoots-Sheet 1 Fig.1.

iiizmng Dec. 6, 1927. 1,652,026

' s. LOFFLER ruurmu rum ron area rasssuns STEM! GENERATORS Filed May 11.1926 3 shoots-sheet 'B aw.

S. LUFFLER PUIPING PLANT FOR HIGH PRESSURE STEAK GENERATORS Dec. 6,1927. 1,652,026

Filed May 11. 1926 3 Sheets-Sheet 3 Patented Dec. 6, 1927. I

UNITED STATES srnrnen Leanna, or cnanno'r'rnnnune, NEAR imanm, enmlm.

PUMPING PLANT FOR HIGH-PRESSURE STEAM GENERATOM' application fled Kay11, 1 926, Serial No. 108,387, and in Germany May 18,

practice the method of generating highcomotive,

tsiressure steam described in my United tates application, Serial Number701,855,

filedv March 25, 1924, in which steam pro-- duced in aboiler is furtherheated outside, and then re-intro'duced into, the same in. order totransmit the added heat to the boiler water and convert this into steam,all as more fully described in said former application.

' a The invention may be embodied in several constructional forms, thecommon charac-i teristic feature ofwhich resides therein that the pumpsconstituting the pumping plant, namely, a steam conveying pump and aboiler feed pump, are driven by an engine or a motor common to themboth, and which is directly connected thereto or geared thereto, theoutput of the two pumps being regulable by varying the number ofrevolutions of the engine or motor. Means may be provided by which theoutput or delivery of the boiler feed pump can be regulated independ:ent of the steam conveyin pump, as is also more fully describedhereinafter.

The invention is illustrated diagrammatically and by way of example onthe accompanying drawings on which Figure 1 is a front view of a pumpingplant designed according to this invention; Figure 2 is a" plan of amodification, "the two 0 linders being shown in horizontal section;igure 3 shows another modification in vertical section: Figure 4 showsagain a modification, in horizontal section; Figs. '5 and 5" showtheinvention applied to a movable plant, viz to a 10- Fig. -5 showing thearrangement and combination of the parts concerned partly in verticalsection and partly in side-view, andFig. 5 showing it gartly inhorizontal section and partly in p an; Figure 6 is a separate sectionsolely throu h the steam conveying pump, together wlth its valvegear andsome other parts; and Figure 7 is a 'diagrammatic representation of thevalve; gear motion, all as more fully dealt with hereinafter, t

Referring to Fig. 1, 1 denotes ;the boiler feed pump, 2 the steamconveying pump, and 3 the engine which is common to both pumps and isassumed, in the example shown, to be anelectromotor. The dimensions ofthe pump cylinders are preferably PATENT OFFICE.

such that the size of the feed pump is chosen dependent upon the size ofthe steam conveying pump,

that is to say, if there are two or more steam conveying pumps thereshould be also two a or' morefe 'umps, always an equal number of pumpsof 0th kinds. 7

In the constructional form shown in Fig. 1, the power. is transmittedfrom thev electromotor 3 to the pumps -1 and 2 by the intermediary ofgearings 4 and 5. .'The output or deliver?l of both pumps can be variedby varying t e number of revolutions of the motor, so that if the pumpsare piston pumps the relation between them is always the same,-

pertaining gearings may be desi ed with consideration of the difierenceof t e characteristics of the two pumps so as to permit to vary theoutput. But instead of particularly designed gearings, a by-pass piperovided with a throttlifigyalve inaybe emp oyed, es-

pecially if the pumps are drivenby a pri-' mary englne, as will be thecase with a loco motive. A byrpass' pipe'becomes, in fact, necessary ifthe boiler feed pump is some what larger than actually required which isi I I to be preferred from certain reasons; that pipe serves also forregulating the output. It 1350f course, possible to combine the twomodes of regulation, viz that; by varyin the number of revolutions ofthe driving. s aft,

as well as that by employing a by-passlpipe with athrottling valve orher. Varying the number 0 the shaft may the number of revolutions ofstrokes'of the engine or the uivalent memwhereas if they are turbinepumps the apbe efiected by varying either 7 number of revolutions of themotor, or by v the intermedia as regards output may In the modifiedconstructional form i lustrated in Fig. 2 the two 'umps 1 and 2 areoperated simultaneously y a crank 3f rotated by the engine 3. The pumpsare arrangedco-axially. The boiler feed pump is provided with -a returnpi regulating member 7 is inserted, and the steamconveying pum isrovi'ded with a rby-pass pipe 8 provi member 9. The return pipe '6 and te lating member 7 may be esigned. similarl of a suitable gearing, and

to the fuel pumps used in connection wit v Diesel engines. g

In Fig. 3 the steam conveyin ump 21's driven directly by the crank o t.e engine,

sole y the boiler feed pump its be varied by varying its stroke.-

fiinto which a.

ed with a regulating".

raga-v I the steam generation can be maintained, with tromotor, or thelike.

whereas the boiler feed pump 1 is driven indirectly from the same crankby the intermediary of a frame 10, whereby the journal pressure isdiminished.

high-pressure steam is warranted.

hile the main engine is at a stand-still,

a correspondingly diminished heating effect, by separate auxiliary pumpsdriven separately, for instance by a steam engine, an elec- According asthe conditions of service at the time being may be, the auxiliary pumpsmay run also while the main engine 18 working, in which case .said pumpswill run continuously; or they are made use of only in the case ofoverloading of the plant in order to increase the steam-production. Itis suited to the purposes of the entire plant to employ the auxiliarypumps also for starting the highpressure steam generator. The umps areto be driven inisuch case by t e driving means or medium available whilethe main engine is at a stand-still, for instance by a low-pressureengine if low-pressure steam is available either in a boileror in anac-.

cumulator; or an electromotor is usedand is fed from a net or a storagebattery. The auxiliary pumps constitute in every case, irrespective ofwhether they run continuously or not, a safet contrivance for theservice, apart from t e-other standb or spare means and safetyappliances per aps provided. a

The output of the main pumps is being variedby varying the number ofrevolutions relatively to the main engine, or b means of a return deviceoperatin in the irection from the delivery side to t a suction side ofthe pumps, or by varying the control gear of the umps, or in any othersuitable manner. "I he auxiliary pumps may work, however, without any relation if the conditions are normal. TE: service is renderedparticularly favorable and simple if the variation of the output ordelivery of the main pumps is efiected in dependency of the steamconsumption of the main engine, i. e. in dependency of the valve controlgear thereof.

Refenrin now to Fig. 4, 11 denotes the cylinder of a high-pressure steamengine constituting the main engine and driving directly a dynamo 12. Atthe free end of the crookedshaft 13 is provided an overhung crank 14driving the boiler feed pump 16, as well as the steam conveying Jump 15(may be, also other pumps required for the proper operation of thehigh-pressure steam instruments, or

feed cylinder or pump.

enerator as for instance a am for conveying cooling water to the stu 'ngboxes of the'piston rod or rods, to the measuring gauges and the like).

For starting t e high-pressure steam generator and for maintaining theproduction of--steam while the main engine is at a standstill, anauxiliary steam conveying pump 17 and an auxiliary boiler feed pum 18are provided and are driven separately by means of an electromotor 20 bythe intermediary of a belt 19 or any 0th is located between the wheels;24, 25 are the steam conveying cylinders and 26 is the The cylinders 21and 24, as well as 23 and 25, are arranged co-axially, the respectivepistons being secured to a continuous piston rod. Also the cylinders 22and 26 are arranged co-axially as shown. The valve control gear of themain driving cylinders has piston slides desi ed according to Heusinger.When the atifiission to these cylinders is varied also the'delivery ofthe main being varied positively of'the main driving cylinders. This mawith the main steam conveying umps, effected, for instance, by varyin te osition umps is pipe 29. The control valve by the va ve control gearan suitable powerv transmitting means. Other auxiliary pumps of acontrol mefnber 28 locate in a y-tpaess gears have n omitted in thefigure.

The steam conveying pum is designed preferably in a manner specialysuited for its purpose, in that the two cylinder sides or ends of thedouble-acting pump are controlled by a positively operated piston slide(without any additional members such, for instance as return valves andthe like} mon to both sides or ends of said cy inder, this slide beingso designed that its lap is nearly zero or, perhaps even negative. Byzero lap I comprehend that simultaneously with the closing of thesuction pipe the pressure pipe is opened, and reversely. The advantageof this constructional form over those that \have become known hithertore-.

com-- neturn-valves and the like, ma

regards pumps working means, especially as as for instance with a veryhigh pressure,

with. a suction pressure of say 100 atmos-' lowermost stages ofregulation; and as sepafor instance, be dispensed with, hi h numbers ofrevo ution can be employe An example of a steam conveying pump designedin accordance with the above stateshown in Fig. 6 in which 30 and 31rate auxiliary members, as,

ments is denote the two sides .orfends of a doubleacting pump, and 32denotes a piston sl de whichis common to both said sides or ends only onsupply opening 33 and only one the gsu plied erhapstoo amply by tu 38 coect at the lowermostvalve casin andleave it throug the aper-,

preferably also for the of the pump. This slide is designed as a hollowslide so that the casing for it. requires delivery opening 34 for thesteam.

The lubrication of the. guide faces for piston and the piston slide sefiected chie a suitable means. In the example illustrated'in Fig. 6bores 35 and .36 of the cylinder and the valve casing are connected bypipes 37 with a helical tube 38 locatedin a vessel through which cooling.water is con, ducted, this water being supplied, for instance, at a,and withdrawn at b. The condensate formin insaid helical ipe flows downto the gulde facesof the cy mder and the valve cas1ng.-

The condensate forming in the cylinder and in the valvecasing and thecondensate the helical 'oint of the ture 39; t is aperture may be,employed I steam from the valve casing.

der and the valve casing" The pump cylin are'manufactured preferablyfrom a solid piece of steel if the pump is, to work with apressure of,say,. 100 or even more atmos-I- pheres. a

The variation of the amountpf steam conveyed by the steam conveyingcylinder may be brought about by a' p ass-shift between the pump pistonand the slide valve, for instance with the aid of an adjustingeccentric.

In the constructional form shown in Fig. 6

. the crank shaft 40 is provided with a wormlike' sleeve 41 which can beshifted axially on said shaft, and is encompassed b an eccentric 42prevented from axial isplacement by any suitable means (not shown).

re-adjusted by an agle B,

. y'by condensate drawn, for instance, 7 from the cylinder and beingthen cooled by discharge O .5118 .1

substantially as set forth. 5 p

3? 2. A: pumping plant for highs m ibn the direction to or from thevalve casing a w brm-like sleeve, whereby the phase-shift is produced.

igure 7 shows gear. the angle a between the centric amounts to crank andthe ec- If'the eccentric is figure, the suction pipe remains the suctionstroke is commencing, and a art of the amount sacked as re-conveyed intothe suction pipe. The action taking. place when the p ston performs itsretlgn the angle between 0 and any maxi quantities of any demovementproceeds correspondingly.- varym mum egree, delive sired amount may ehad between those limits. In order to prevent the arising of pressureshocks while the plant is inoperadelivered'is somewhat considerablydiminished, the laps of the slidevalve' are adjusted to zero or even tonegative, that is to say as already explained,-t e delivery pipe isclosed simultaneously'with the opening of the suction pi e, andreversely, or, in other words, the cy inder is connected with thesuction pipe, aswellas withthe delivery pipe when the suction stroke ischanged into 'the delivery stroke, and reversely.

A control gear ofthis k 'nd is suited especially in those cases in whichthe steam conveying engine, pump with a separate driving engine or motormust be provided for the starting of the steam generator. I I claim:f." 1. A pumping plant for highressure steam generators of the kind inwich the steam 1s generated by steam heated outside the boiler andintroduced or reintroduced mt o the water of the same, said plant.comprlsing a. steam conveying pump, a boiler feed um an en ine or amotor adapted a diagram of the 'valve' At the maximum output or deliveryas indicated in the open when w ump is to be driven by themain ut, then,of course. an auxiliary.

'The eccentric can be moved more or less a corresponding axial shiftingof said as may occur especially if-the amount 1 todrive oth sai pum s,and meansifor' varying the output or de ivery ofthej same,

ressure enerators of the kind in w steam is generated by steam heatedoutside the boiler and introduced or reintroduced. into the water of thesame, said plant comprising a steam conveying pumpya boiler ichthe eedpum an engine or a motor adaptedto j drive hot the output separately,

3. A. "pumping steam enerators o substantiallyas set forth.

lant for highressure the kind in w ich the steam 1s generated by steamheated outside the boiler and introduced or reintroduced into the waterof the same, said plant compumps and means for. varying or deliyery ofboth said pum'ps/ prising a piston pump adapted to be used as steamconveying pump, another piston pump adapted to be used as boiler feedsump, an engine or a motor adapted to rive said steamconveying pump,means for transmitting the driving power from the driving gear of saidlatter pump to said feed pum and means for varying the output or deivery of this pump, substantially as set forth. a I

4. A pumping plant for highressure steam enerators of the-kind in wiichthe steam is generated by steam heated outside the boiler and introducedor reintroduced into the water of the same, said plant comprising adouble-acting steam conveying pump, a positively moved piston slidevalve adapted to co-operate with both sides or endsof said pump andhaving laps amounting to zero or being even negative; a boiler feedpump, an engine or a motor adapted to drive both said'pumps, and meansfor varying the output or delivery of the same, substantially as setforth.

' 5. A pumping plant for high: ressure steam generators of the kind in wrich the steam is generated by steam heated outside the boiler andintroduced or reintroduced into the water of the same, said plantcomprising a double-acting steam conveying pump, a positively movediston slide valve adapted to co-operate with 0th sides or ends of saidpump and having laps amounting to zero or being even negative, and acondensate collecting chamber having a discharge opening; a boiler feedpump, an engine or a motor adapted to drive both said pumps, and meansfor varying the output or delivery of the same, substantially as setforth.

6. A pumping plant for high-pressure steam generators o the kind inwhich the steam 1s generatedby steam heated outside the boiler andintroduced or reintroduced into the water of the vsame, said plantcomprising a double-acting steam conveying pump, a positively movedpiston slide valve adapted to co-operate with both sides or ends of saidpump and having laps amounting to zero or being even negative; a steamcondensing device so arranged as to be adapted to deliver lubricatingcondensate to the guide surfaces of he pistons a boiler feed pump, anengine or a motor adapted to drive both said pumps, and means for varing the output or delivery of thesame, su stantially as set forth.

A pumping plant for highressure steam generators of the kind in w ichthe steam 1s generated by steam heated outside the boiler and introducedor reintroduced into the water of the same, said plant comprising adouble-acting steam conveying pump, a positively moved piston slidevalve adapted to co-operate with both sides or ends of said pump andhaving laps amounting to zero or being even negative; means for varyingthe output of the steam conveying pump by varyin the phase-shift betweenthe piston and t e valve gear thereof; a boiler feed pump, an engine ora motor adapted to drive both said pumps, and means for varying theoutput or delivery of the same, substantially as set forth.

In witness whereof I have hereunto set my hand.

STEPHAN LOFFLER.

